Passive Optical Networks

In addition, we can see from the example that the delay incurred on shorter

packets from the second queue is also reduced.

The problem with this WFQ scheduler is the expense in implementing the

virtual round-robin algorithm. Because of this, various schedulers have been

suggested which can be implemented at a lower cost [10–13]. More details can be

found from these references.

Now, when we apply the Fair Queuing technique to the upstream transmis-

sion of a PON system, the queues correspond to individual ONUs and the

scheduler corresponds to the DBA at the OLT. However, in this case, it would

be difficult to install WFQ as DBA without modification due to the following

constraints:

1. Only limited information transmitted from the ONU can be identified ...